Method of treating freshly pasted storage battery plates



c. c. ROSE 2,068,434

' METHOD OF TREATING FRESHLY PASTED STORAGE BATTERY PLATES Jan. 19, 1937.

Filed April 17, 1956 INVENTOR.

1 A [5112? ATTORNEYS apes/vas- CI P055 Y mn l l lnl l lrl Patented Jan. 19, 1937 METHOD OF TREATING FRESHLY PASTED STORAGE BATTERY PLATES Clarence 0. Rose, Mentor, Ohio, assignor to Willard Storage Battery Company,

Cleveland,

Ohio, a corporation of West Virginia Application April 17, 1936, Serial No. 75,027

' .13Claims. v(c1. 136-78) This invention relates to a method oftreating freshly pasted storage battery plates, and has reference particularly to the treatment ofplates,

for lead-acid batteries in .such manner as to make possible the stacking'of theplates after pasting without having them stick to each other.

In the present prevailing methods for handling storage battery plates of this type between the operations of pasting and charging, the plates after being pasted must be handled individually, that isplaced in racks so that their surfaces are separated, and then maintained for some hours in an atmosphere of controlled temperature and humidity. Then while so racked they are put 5 through drying ovens in order-that the moisture present in thepaste may be expelled. Thereafter they must be wetted again and then stacked and kept in storage under proper conditions -to give satisfactory battery capacity and life char-' 30 acteristics.

One of theobjects of the present'invention is the eliminationof some of these steps by so treating plates immediately after they are pasted,

' and without handling them at all, that they may 5 be piled in stacks one upon another without danger of sticking together, whereby the storing and aging process may be entered into at once without the usual setting and drying steps which were necessary-in the prior procedure.

' 3Q ting is also not required.

40 Figl 2 is a vertical cross sectional view taken substantially-on the line 22 of Fig. 1. e

In the drawing I0 isa paste hopper with its open bottom end arranged in close proximity to theupper surface of an endless belt ll,.or other 45 means for conveying grids up to the paster -and for conveying the pasted plates away from the I paster. The pasted plates, as they leave the conveyor l l are delivered-onto a conveyor of special construction comprising a, pair of spaced endless 50 chains f I2' which at frequent intervals carry fingers I35 projecting inwardly toward each other,

to an extent suflicient to support the edges of the plates, one ofwhi'ch is indicated-in dotted lines at P, Fig. 2. In this manner'practically the en- 55 tire upper and lowersurfaces 01' the plates are,

left exposed and unobstructed. The upper runs of the chains I2 aresupported and guided in rails l4. To the tops of these rails I attach guard or guide strips l5, which maintain the plates in alignment as theyv are carried along by the chains.

The chains I2 and the rails M are supported in a frame iii of suitable character which also carries upper and lower sets of gas or other fluid burners I1 and I8. These burners extend transn- 1 versely substantially across the width. of they plate, and are spaced far enough away from the plate to cause the tips of the flames from the burners to impinge upon the upper and lower surfaces of the plate. The number of these burners may be varied to suit conditions. Obviously the speed of travel of the chains I2 is an important factor in determining the number of burners required for a given result.

The upper burners are conveniently mounted as a unit, which is capable of being swung up in I a parallelogram movement by means of links I 9,

thereby providing access to the conveyor at that point. 'The lower set of burners is likewise conveniently mounted as a unit, and may be mounted 5 similarly to the upper set if desired, but as herein illustrated this unit is supported rigidly in the frame. In both cases-thereis preferably provision for adjustment so that the distance of the burners irom the plates may be varied to a small 1 extent. Gas mixed with air is supplied .to the burners through pipes 20 and M. The gas is fuel gas, preferably natural gas. The proportion of 'air is very carefully maintainedat a level such that the products of combustion shall be'carbondi oxide primarily. Any carbon monoxide which may be present is in such small quantities as to be negligible. Hence'the plates are subjected" progressively on both pasted surfaces to evenly 40 distributed streams of carbon dioxide in the presence of heat.

When the plates, have traversed the path between the two sets of burners their treatment is completed, except that they are preferably given I time to cool, which procedure promotes some further evaporation of moisture. They may then be lifted off the carrier by an attendant and stacked in piles, or collected in a suitable automatically acting take-01f, apparatus. While I usethe blue tip or oxidizing portion of the flame, I do so because that portion is the hottest and not because .of its oxidizing efiect. However, his important not to use a reducing name, because that would be detrimental in that it would reduce the lead oxide of the paste to metallic lead, which would form in globules under the effect of the heat.

The carbon. dioxide combines with the lead oxide of the paste to form lead carbonate, at least upon the surfaces of the plate. This compound functions in some manner to prevent the heat from the flames cracking the paste, that is if the heat isnot too great or maintained too long on a given area. The application of heat in accordance with the invention is a somewhat critilong enough the plates will stick together when cal treatment, that is to say if it is not continued stacked in piles, and if it is continued too long cracking of the paste will occur. I have found by tests that the heat thus applied-should be suflicient to reduce the moisture content of the paste to the extent that water shall constitute from 9% to 11% of the total weight of the paste. This compares with a proportion of 12 to 13% of Water to the total before the plate is subjected to the flames.

' Since the flames are close to the plate, the spacing of the burners from the plates being only a fraction of an inch, the carbon dioxide formed in the flames impinges directly on the surfaces .of the 'plate without becoming mixed with air, and

furthermore the flame concentrates heat at the same point, which assists in the chemical action as well as promoting the partial or surface drying of the paste.

I cannot state the exact reason for the action of the lead carbonate formation on the paste in preventing cracking thereof when the stated amount of moisture is quickly expelled from the paste. I do know however that, by the use of a gas flame containing carbon dioxide as the principal product of combustion, a freshly pasted battery plate can tolerate rapid drying to the extent that the plates may be practically 'and economically handled mechanically and compactly stacked in piles and placed in storage for subsequent processing.

Having thus described my invention, I claim:

I. The method of drying freshly pasted plates for storage batteries of the lead-acid type, which comprises playing directly upon pasted portions of the plates a flame containing carbon dioxide.

2. The method of treating freshly pasted plates,

for storage batteries of the lead-acid type, whi ch comprises playing directly upon the pasted portions of the plates' on each side thereof flames containing carbon dioxide.

3. The method of treating freshly pasted plates for storage batteries of the lead-acid type, which comprises subjecting all pasted portions of the plates on each side thereof for a brief period to the direct action of a flame containing carbon dioxide.

4. The method of treating freshly pasted plates for storage batteries of the lead-acid type, which comprises subjecting all pasted portions of the plates on each side thereof to the direct action of a flame containing carbon dioxide for. a period long enough to reduce the weight of moisture in the paste to approximately 10% of the total paste weight.

5. The method of treating freshly pasted plates for storage batteries of the lead-acid type, which comprises subjecting all pasted portions of the I for storage batteries of the lead-acid type, which comprises subjecting all pasted portions of the plates successively on each side thereof to the direct action of flames containing carbon dioxide.

8. The method of treating freshly pasted plates for storage batteries of the lead-acid type, which comprises conveying the plates flatwise between a pair of transversely arranged lines of flames containing carbon dioxide and playing directly upon the pasted surfaces.

9. The method of treating freshly pastedplates for storage batteries of. the lead-acid type, which comprises subjecting successively all pasted surface areas of the plate to the action of carbon dioxide accompanied by a flame applied directly to the same areas simultaneously with the carbon dioxide.

10. The method of treating freshly pasted plates for storage batteries of the lead-acid type, which comprises playing upon the surface of the plate the flame from an ignited mixture of fuel gas and air, and thereby'causing carbon dioxide produced by the combustion in the flame to react with the lead oxides of the paste to form a coating of lead'carbonate.

11. The method of treating freshly pasted plates for storage batteries of the lead-acid type, which comprises playing upon the surface of the plate the flame from an ignited mixture of fuel gas and air, thereby causing carbon dioxide produced by lead oxides of the paste to form a coating of lead carbonate, and at the same time drying the paste at and near the surface of the plate.

12. The method of treating freshly pasted plates for storage batteries of the lead-acid type, which comprises playing upon the surface of the plate a flame produced by mixing with a fluid fuel sufficient air to form carbon dioxide as the principal product of combustion in the flame, thereby causing the carbon dioxide of the flame to react with the lead oxides of the paste at the surface of the plate to form a coating of lead carbonate.

13. The method of treating freshly pasted plates for storage batteries of the lead-acid type, which comprises playing upon the surface of theplate a flame produced by mixing with a fluid fuel sufficient air to form carbon dioxide as the principal product of combustion in the flame, thereby causing the carbon dioxide of the flame to react with the lead oxides of the paste. at the surface of the plate to form a coating of lead carbonate, the

-the combustion in the flame to react with the heat from the flame facilitating the said reaction and serving further to dry the paste at least at the surface of the plate.

CLARENCE c. ROSE. 

